Dropout half-tone negative



March 30, 1943. ZUKMANN 2,315,101

DROP-OUT HALF-TONE NEGATIVE Filed July 29, 1941 3 Sheets-Sheet lINVENTOR [0.5210 Zak/22mm March 30; 1943.

L. ZUKMANN 2,315,101 DROP-OUT HALF-TONE NEGATIVE Filed July 29, 1941 3Sheets-Sheet 2 INVENTOR t Qaszlo Zak/220121;

March 30, 1943. ZUKMANN DROP-OUT HALF-TONE NEGATIVE Filed July 29, 19413 Sheets-Sheet 3 INVENTOR. lasz/a Z zl/i ma/m Patented Mar. 30, 1943UNITED STATES PATENT OFFICE- 2,315,101 nnorou'r HALF-TONE NEGATIVELaszlo Zukmann, New York, N. Y. Application July 29, 1941, Serial No.404,572

. 24 Claims.- (01. 95-5) This invention relates to a' new and improvedprocess of preparing printing plates and more particularly to a processof eliminating all screening or dots in the background or high-lightsections of a half-tone positive or negative. This process isparticularly adaptable for the type of photoengraving and illustrationcommonly used for newspaper advertising.

An object of this invention is to provide a simple process ofhigh-lighting which is tree from the prevailing, lengthy, andinexpedient methods.

Another object of this invention is to provide a process which willgreatly diminish the necessity of using skilled labor and which willfacilitate the production of printing plates.

Briefly, the proposed new process comprises the following steps:

First, from an original drawing having highlight and tone sections isprepared a negative, having substantially transparent portionscorresponding to the tone sections, and substantially opaque portionscorresponding to the high-light sections of the original drawing. In thefollowing description such a negative will be called half tone masknegative. has also line sections which should be reproduced as opaquecontinuous lines, first a negative is prepared which; has transparentportions corresponding to the tone and line sections, and opaqueportions corresponding to the high-light sections of the originaldrawing. In the following, such a negative will be called a "half toneand line mask negative.

Thereafter is prepared a positive having substantially opaque portionscorresponding to the tone sections, and substantially transparentportions corresponding to the high-light sections of the originaldrawing. In the following description such a positive will be called ahalf tone mask positive. If the original drawing contains also linesections which should be reproduced as opaque continuous lines, the maskpositive will also have opaque portions corresponding to these linesections; in the following such a positive will be called a. half toneand line mask positive.

In case the original drawing contains only high ight and tone sections,the next step -will consist in photographing the original drawing on alight-sensitive photographic material successively through the abovedefined half-tone mask negative and half-tone mask positive in such amanner that a half-tone screen is interposed between the drawing and thelight-sensitive material when the drawing is photographed throughthehalf-tone mask negative. In case the original If the originaldrawing.

drawing contains also live sections, the original drawing may bephotographed through a halftone and line mask positive instead of thehalf-,- tone mask positive mentioned above.

This new process results in a drop-out halftone negative having opaqueportions correspond ing to the high-light sections, and half-toneportions corresponding to the tone sections of the original drawing. Incase the original contains also lines, i. e. is a combination of tone,line, and high-light sections, the new process results in a drop-outhalt tone and line negative having opaque portions corresponding to thehigh-light sections, 'hal-f tone portions corresponding to the tonesections,

I and transparent portions corresponding to the line sections of theoriginal drawing.

It should :be noted that throughout this application the term,high-light" is used to desigmate the sections of an illustration ordrawing which are required to be printed in reproduction as pure \white,orasfree from screen pattern, and

is usually considered as referring to background or white? sections ofan illustration. The term, "tone sections refers to the shaded or darkparts of an illustration. The term, line sections" refers to thecontinuous opaque lines appearing on an illustration. These terms arealso to indicate areas on a negative which correspond to the designatedsections in the original illustration.

Furthermore, it should be noted that the term, "negative" is usedthroughout thespeciflcation to designate photographic reproductions onwhatever type of photographic material in which the high-light sectionsof the illustration appear opaque and the tone sections appear more orless transparent. In'the same way, the term, positive designatesphotographic reproduction on whatever kind of photographic aterial, i.e., on

paper, film, or photographic pla e, in which the this white backgroundhas to be reproduced without screening.

The novel features which I consider as characteristic for my inventionare set forth in particular in theappended claims. The inventionitseli', however, both as to its construction and.

its method of operation. together with additional objects andladvantagesthereof will be best understood from, the Iollowing description oi.specific embodiments, when'read in connection with the accompanyingdrawings, in which:

Fig. 1 illustrates a type of drawing having tone and high-light sectionswhere, in. printed reproduction, elimination of half tones isrequired-inthe high-light sections. i. e. in the sections shown in thifigure in pure'white; I h h Fig. 2 represents a continuous tone negativemade fromthedrawingshown inFig. 1; 1

Fig. 3 shows a halt .tone mask negative 'made' out half tone negativefrom the original shown in Fig.

A Fig. 8 is a drop-out half-tone negative made in accordance with thepresent invention;

Fig-.9 illustrates a type of drawing having tone,

line; and high-light sections;

Fig. represents a continuous tone negative made from the drawing shownin Fig. 9:

. and? are expanded views oi photo j graphic arrangements used formaking'a drop- ';high-light sections 2|.and transparent portions 28corresponding to the tone sections 22 of the positive shown'in Fig. 4,is superimposed onthex graphic step results in exposure of all the por-"I tions of the light-sensitive surface of photographoriginal drawing.

Third steps-From this half tone masknega tive 2-i't'he half-tone maskpositive 28, shown in Fig. 4 is made, by printing the same on aphotographic material consisting of a transparent basepro'vided'with alight-sensitive layer. After exposure, the print. is treated in theusualway undresults in' ahali-tone mask positive having transparentportions 29 corresponding to the high-light sections 2|, and opaqueportions 30 corresponding to Fourth step-Thereafter, the half tonezrnaskoriginal drawing in, the way shown in Fig. 6, and

the original drawing 20 photographed through; the half tonemask positive28 onto the lightsensitive photographic material 3|. This photoicmaterial 3i corresponding t the high-light sections 2| of-the originaldrawing which are covered onhr' bythe' transparent-portions 29 of'th'e 1halt tone mask positive, 28 superimposed on the drawing 20; thoseportions of the light-sensitive "surface 01 photographic material 3|which corre- Fig. 111- represents a half tone and line mask' negativemade from the;cont inuou tonenega:

tive shown in Fig. 10;

Fig. 12 shows a half tive printed'irom the half tone and linemasknegative shown in Fig. 11; j

Fig.'13shows a half tone masknegative produced by retouching the halftone and line mask negative shown in Fig. 11; I

Fig. 14 shows a halt tone mask positive produced by printing the halftone mask negative shown in Fig. i3; and

Figs. 15, 16, and 17 are expanded views of photographic arrangementsused for making a dropout half tone and line negative from the originalshown in Fig. 9; and I Fig. 18 is a drop-out half-tone and line negativemade in accordance with the present invenion.

t The process of producing a drop-out half tone negative from theoriginal drawing 20 having, as shown in Fig. 1, high-light sections 2|and tone sections 22, comprises in accordance with one embodiment of thepresent invention the following steps:

in Fig. 1, the continuous tone negative 2I shown in Fig. 2 is made. Thiscontinuous tone negative.

has opaque portions 22 corresponding to the highlight siection's', andnegative tonepo'rtions 2i correspondingto the positive tone sections 22of the originaldrawing 28. This continuous tone negative ismade in theusual way.

Second step-From this continuous tone negative the half tone masknegative shown in Fig. 3 is made by treating the continuous tonenegative, shown in Fig. 2. while still wet with a photographic reduceruntil the tones oi the tone portions disappear; thereafter, the I thusproduced half tone mask negative is fixed. washed, and finally dried.This results in the half tone mask negative shown in Fig. 3; this masknegative has opaque portions 21* correspond g to the tone line maskposispond to the tone sections 22 of the original drawing'and arecovered by the opaque portions 30 of the half tone positive, remainunexposed.

Fifth. step-Thereafter, the half tone mask positive 28 is removed andreplaced by the half tone mask negative 26; it must be stressed thatthis change must be carried out without altering the relative positionof the original drawing-20 w and the partly exposed light-sensitivephotographic material 3|.' The halftone screen 32 i consistingot opaquescreening lines 33 on a transparent base 34 is placedbetween the halfgraphic material 3|. As those surface portions of the photographicmaterial 3| which correspond to the tone sections 22 are stillunexposed, this exposure results in a screened, i. e. half tone negativeimage of the positive tone sections 22 of the original drawing on theseunexposed por- 1 tions of the photographic material 3|.

Sixth step.The photographic negative ma- .terial is then developed,fixed, washed, and dried.

as usual in making negatives. This treatment results in the drop-outhalf tone negative 32' shown in Fig. 8; this drop-out half tone negativehas, in accordance with the present invention, opaque portions 38'corresponding to the highand line negatives.

light sections 2|, and half tone, i. e'.; screened negative toneportions 34' corresponding to the positive tone sections 22 01' theoriginal drawing 20.

As stated above, the present process is particularly adapted forproducing drop-out half tone Such negatives are to be made from drawingsof the type shown in Fig. 9; such drawings 35 have high-light section38, tone sections 21 and line sections 38. The process of producing fromsuch a drawing a drop-out and half tone line negative comprises, inaccordance with one preferred embodiment of the present invention thefollowing steps:

Step one-From theoriginal drawing shown in Fig. 9, the continuous tonenegative 39 is made h tonesections 22 of the'ori'g. 1 a ing-22. i

aerator in the usual way. As shown in Fig. 10, this continuous tonenegative "has; opaque portions 40 corresponding to the ,high-lightsections .36, transparent portions 4| corresponding to the line sections38, and negative tone sections 4'! terial u is then developed. fixed.when, aid

corresponding to the positive. tone sections 31 of 3 the originaldrawing 35. I

Step two..-From. this continuoustone negative 3! is made the half toneand line mask negative 43, shown in Fig. 11, in the way described above.

This mask negative 43 hasv opaqueportions 44 corresponding to.thehigh-light sections, and transparent portions 45 and 45 corresponding tothe line sections 38 and tone sections 31, respectively, of .theoriginal drawing.

Step three..From this half tone and line mask negative 43, shown in Fig.11, the half tone and line mask positive 41, shown in Fig. 12,.is madeby photographic printing. This half tone and line mask .positive 41hastransparentportions 48 corresponding to the high-light sections 36,

and opaque. portions 43 and corresponding to the line sections and tonesections 31, respectively, of the, original drawing35. I

Step four.-Thereafter, the half tone and line mask negative 43, shown inFig. 11, is transformed by opaquing the transparent line portions 54into the half tone mask negative 5|, shown in Fig. 13. This masknegative 5| has opaque portions 52 and 53 corresponding to thehigh-light sections 35, and line sections 38, respectively, and hastransparent portions 54 corresponding to the tone sec.- tions 31 of theoriginal drawing 35.

Step five.-Having thus made the half tone and line mask positive 41 andthe half tone mask.

negative 5|, and having at disposal also the half tone screen 32 shownin Fig. 5, the original drawing is photographed indifferent combinationswith these masks and the screen: As shown in Fig. 15, thehalf tone andline mask positive 41 is superimposed on the original drawing 35 and thedrawing is photographed through this mask on the light-sensitivephotographic material 55 consisting of a light-sensitive emulsion on atransparent base. After exposure, the mask 41 is removed withoutaltering the relative posi- .tone portions 53 corresponding dried asusualin making negatives. -This treat ment results in' the drop-outhalftone and line negative 55, shown in Fig. 18; this drop-out half tone andline'negative h as', in accordance with the present invention, opaqueportions 51 corresponding to the high-light section 35, transparent:portions 55 corresponding to the line sections 38, and half tone, ire.screened negative to the tone sec tions 31 of the original drawing.

Step-eight.-As well known in making half tone screen negatives, it isexpedient to perform another operation which is universally used and iscalled, flashing. Without this'fla'shing there would be no screening inthe darker parts of the halfv tone portionsof the negative because thecorresponding sections of the original drawing reflect little or nolight. 'The" purposeof the flashing is to create this screening in thedarker half tone portion of the negative." If this flashing operationwere performed in the usual way, the screening would appear not only inthe half tone portions but also in the line portions of the negative;the continuity and transparency of these line portions would thereby bebroken up and the object of the present invention defeated.

tion of the drawing 35 and the photographic material 55.

Step sin-Thereafter, the half tone mask neeative 5| is superimposed onthe original drawing 35 and the half tone screen 32 is interposedbetween this half tone negative 5| and the lightsensitive photographicmaterial 55. (See Fig. 16.) In view of the fact that duringphotographing the drawing through the half tone and line mask positive41 in the way described above, the lightsensitive layer of thephotographic negative material 55 will have been exposedonly by thehighlight sections of the ori inal drawin those portions of the liht-sensitive layer which correspond to the line and tone portions 49 and50 of the mask positive 41 remain unexposed. Now, when photographing thedrawing through the half tone mask negative 5| only those portionsof thenegative material which correspond to the tone portions 54 of the maskne ative 5| will be exposed. while all other portions. particularly theunexposed line portions remain unexposed. As the tone sections 31' ofthe ori nal drawing are photographed through screen 32 and thetransparent tone portions 54 of the mask negative 5|, they will finallyappear onthe negative photographic material 55 as half tone, 1. e.screened tone portions. u

Step seven The negative photographic ma This difiiculty is overcome byflashing through the half tone mask negative 5|, as-shown in Fig. 17. Inperforming the flashing'op'eration, a sheet of white paper 50* is"placed immediately behind mask 5| replacing the originaldrawing 35,orarranged between this drawing and'the mask. Since on the half tonemask negative 5| all portions corresponding to the line sections 38 havebeen retouched, i; e. painted out,"an'd since all portions correspondingto the high-lightse'c tions 36 are. opaque, the portions of'the negativecorresponding to these high-light and line'sec tions remain, also afterflashing, free --from screening, but the half tone portions appear alsoin the darker parts with screening.

From the drop-out half tone and line negative produced in the abovedescribed way, the next stages of the usual'process can be carried outeither by operating directly on the zinc plate or by making a positive,whichever happens to be more convenient. a 3

Although the above described embodiments are the preferred ones,modifications of the new process within the limits of thepre'sentinvention are possible. Such modifications are, for instance, thefollowing? It is possible to reverse the i. e.',

photographic. steps. to photograph the original drawing first throughthe mask negative and the screen, and then through the mask positive.This reversed process has the same result as the above describedprocesses: I

Furthermore. in the process of making a dropout half tone and linenegative, it is possible to use a half tone mask positive of the typeshown in Fig. 14 instead of the half tone and line mask positive 41"shown in Fig. 12. This half tone mask positive could be used forthe-process step shown in Fi 15 with the same result, 1. e. withoutaltering thepicture produced by this step on the light-sensitivephotographic material 55.

This is caused by the fact that theline sections 38of the originaldrawing 35 are also opaque I and, therefore. it'is unnecessary tosuperimpose upon these opaque line sections 35 of the ori inal drawingthe opaque portions '43 of the.

hali'tone and line maskpositive 41.

Furthermore, it is also possible to prevent the I flashing o! theunexposed line portions on the final negative by another method than theone described above This other method consists in using for the processstep shown in Fig. 16 the half tone and line mask negative 43 shown inFig. 11 instead of the retouched hali' tone mask negative 5i shown inFig. 18. This mask negative 43, however, is not superimposed on the 7original drawing in register with the same, but

What is claimed as invention and desired to.

be secured by Letters Patent oi the United States is: v

l. In a process of producing a drop-out halt tone negative from anoriginal drawing comprising highlight and tone sections, the steps ofmaking a halt tone mask negative having substantially transparentportions corresponding to the tone sections and substantially op ueportions corresponding to the highlight sections of the originaldrawing, making a hail tone mask positive comprising substantiallyopaque portions corresponding to the tone sections and substantiallytransparent portions corresponding to the highlight sections of theoriginal drawing, and photographing said original drawing on alightsensitive photographic material successively through each of saidmasks with, a half tone screen interposed between the drawing and thelight-sensitive material when the drawing is photographed through thehall. tone mask negative.

2. In a process of producing a drop-out half tone negative from anoriginal drawing comprising highlight and tone sections, the steps ofmaking a halt tone mask negative having substantially transparentportions corresponding to the tone sections and substantially opaqueportions corresponding to the highlight sections of the originaldrawing, making a half tone mask positive comprising substantiallyopaque portions corresponding to the tone sections and substantiallytransparent portions corresponding to the highlight sections or theoriginal drawin superimposing said masks one after another unto saidoriginal drawing, and photographing said drawing on-a light-sensitivephotographic material through each of said superimposed masks with ahalf tone screen interposed between said drawing. and saidlight-sensitive material when the drawing is photographed through thehalf tone mask negative.

3. In a process of producing a drop-out half tone and line negative froman original drawing having highlight, line and tone sections, the stepsof making a half tone mask negative having substantially transparentportions corresponding to the tone sections and substantially opaqueportions corresponding to the highlight and line sections of theoriginal drawing, making a hall tone mask positive having substantiallyopaque portions corresponding to the tone sections and substantiallytransparent portions corresponding to the highlight and line sections ofthe original drawing, and photographing the original drawing on alight-sensitive photographic material successively through each of saidmask; with a hali' tone screen interposed between the drawing and thelight-sensitive material when the drawg negative.

ing is photographed through the half tone mask 4. In a process oiproducing a drop-out tone and line negative from an original drawinhaving highlight, line and tone sections, the

one after another unto said original drawing,

and photographing said drawing on a light-sensitlve photographicmaterial through each of said superimposed masks with a half tone screeninterposed between said drawing and said lightsensitive material whenthe drawing is photo-' graphed through the half tone mask negative.

5. In a process 01' producing a drop-out half tone and line negativefrom an original drawing having highlight, line and tone sections, the

steps of making a half-tone mask negative having substantiallytransparent portions corresponding to the tone sections andsubstantially opaque portions corresponding to the highlight and linesections of the original drawing, making a halt tone and line maskpositive having substantially opaque portions corresponding to the toneand line sections and substantially transparent portions correspondingto the highlight sections oi the original drawing, superimposing saidmasks one after another unto said original drawing, and photographingsaid drawing on a light-sensitive photographic material through each oi.said superimposed masks with a half tone screen interposed between saiddrawing and said light-sensitive material when the drawing isphotographed through the half tone mask negative.

6. In a process 0! producing a drop-out halt tone negative from anoriginal drawing having highlight and tone sections, the steps of makinga halt tone mask negative having substantially transparent portionscorresponding to,the tone sections and substantially opaque portionscorresponding to the highlight sections oi! the original drawing, makinga half tone mask positive having substantially opaque portionscorresponding to the tone sections and substantially transparentportions corresponding to the highlight sections of the originaldrawing, photographing the original drawing on a light-sensitivephotographic material first through said half tone mask positive, andthen photographing said original drawing again on the samelight-sensitive material through said half tone mask ngative and a halltone screen interposed between said mask and the light-sensitivephotographic material.

'1. In a process of producing a drop-out half tone negative from anoriginal drawing having highlight and tone sections, the steps of makinga halt tone mask negative having substantially transparent portionscorresponding to the tone sections and substantially opaque portionscorresponding to the highlight sections of the original drawing, makinga halt tone mask positive having substantially opaque portionscorresponding to the tone sections and substantially transparentportions corresponding to the highlight sections of the originaldrawing, superimposing said halt tone mask positive on said originaldrawing,

photographing the same throughsaid superimposed mask positive on alight-sensitive photographic material, removing said mask positive,superimposing on said drawing said hall tone mask negative, interposingbetween said superimposed mask negative and said light-sensitivephotographic material a half tone screen and photographing said drawingthrough said mask negative and said half tone screen on thelightsensitive material without altering the relative position of thedrawing and the light-sensitive material. A

8. In a process of producing a drop-out half tone and line negative froman original drawing, having highlight, line and tone sections, the stepsof making a half tone mask negative having substantially transparentportions corresponding to the tone sections and substantially opaqueportions corresponding to the highlight and line sections of theoriginal drawing, making a hall tone mask positive having substantiallyopaque portions corresponding to the tone sections and substantiallytransparent portions corresponding to the highlight and line sections ofthe original drawing, photographing thereafter the original drawing on alight-sensitive photographic mate rialfirst through said half-tone maskpositive, and then photographing said original drawing again on the samelight-sensitive material through said half tone mask negative, and ahalt tone screen interposed between said mask and the light-sensitivephotographic material.

9. In'a process of producing a drop-out half tone and 'line negativefrom an original having highlight, line, and tone sections, the steps ofmaking a hall tone mask negative having substantially transparentportions corresponding to the tone sections and substantially opaqueportions corresponding tothe'highlight and line sections oithe originaldrawing, making a half tone mask positive having substantially opaqueportions corresponding to the tone sections and substantiallytransparent portions corresponding to the highlight and line sections ofthe original drawing, superimposing said half tone mask positive on saidoriginal drawing, photographing the same through said superimposed maskpositive on a light-sensitive photographic material, removing said maskpositive, superimposing on said drawing aid half tone mask negative,interposing between said superimposed mask negative and saidlight-sensitive photographic material-a hali' tone screen, andphotographing said drawing through said mask negative and said halt tonescreen on the lightsensitive material without altering the relativeposition of the drawing and the light-sensitive material.

10. In a process of tone and line negative from having highlight, lineand tone sections, the steps of making a halt tone mask negative havingsubstantially transparent portions corresponding to the tone sectionsand substantially opaque portions corresponding to the highlight andline sections of the original drawing, making a halt tone and line maskpositive having substantially opaque portions corresponding to the toneand line sections and substantially transparent portions correspondingto the highlight sections of the original drawing, photographing theoriginal drawing on a light-sensiproducing a drop-out half an originaldrawing drawin material.

tive photographic material that through said halt tone and line maskpositive, and then ph graphing said original drawing {again on the samelight-sensitive material through said half tone mask negative and a halttone screen interposed between said mask negative and the lightsensitivephotographic material.

11. In a process oi producing a drop-out half tone and line negativefrom an original drawing having highlight, line and tone sections, thesteps of making halt tone masknegative having substantially transparentportions corresponding to the tone sections and substantially opaqueportions corresponding to the highlight and line sections of theoriginal drawing, making a halt tone and line mask positive havingsubstantially opaque portions corresponding to the tone and linesections and substantially transparent portions corresponding to thehighlight sections of the original drawing, superimposing said halt toneand line mask positive on said original drawing, photographing the samethrough said superimposed mask positive on a light-sensitivephotographic material, removing said mask positive, superimposing onsaid drawing said half tone mask negative, interposing between saidsuperimposed mask negative and said light-sensitive photographicmaterial a hall tone screen, and photographing said drawing through saidmask negative and said half tone screen on sensitive material withoutaltering the relative position of the drawing and the light-sensitive12. In a process of producing a drop-out half tonenegative from anoriginal drawing,- having highlight and tone sections, the steps ofphotographically making a halt tone mask negative having substantiallytransparent portions corresponding to the tone sections andsubstantially opaque portions corresponding to the :highlight sectionsof the original tone mask positive having substantially opaque portionscorresponding to the tone sections and substantially transparentportions corresponding to the highlight sections of the original drawingby preparing a photographic print of said half tone mask negative,superimposing said masks one after another unto said original drawing,and photographing sensitive photographic material through each 01 saidsuperimposed masks separately in such a manner that a half tone screenis interposed between said drawing and said light-sensitive materialwhen the drawing is photographed through the hall tone mask negative.

13. In a process of producing a drop-out halt tone and line negativefrom an original drawing having highlight, line and tone sections, thesteps of photographically making a half tone mask negative havingsubstantially transparent portions corresponding to the tone sectionsand substantially opaque portions corresponding to the highlight andline sections of the original drawing, making a halt tone mask positivehaving substantially opaque portions corresponding to the tone sectionsand substantially transparent portions corresponding to the highlightand line sections of the original drawing by preparing a photographicprint of said half tone mask negative, and photographing said originaldrawing on a light-sensitive photographic material successively througheach of said masks with a half tone screen interposed between thedrawing and the-light-sensitive material when the drawthe light- 7drawing, making a halt said drawing on a lightdrawing, making a halltone and line mask positive having substantially opaque portionscorrespondingto the tone and line sections and subs ntially transparentportions corresponding to the highlight sections of the original drawingby preparing a photographic print of said halt tone and line masknegative, making from said ball tone and line mask negative by opaquingthe transparent line portions of said negative a halt tone masknegative, superimposing said halt tone mask negative and said halt toneand line mask positive onto said original drawing in either succession,and photographing said drawing on a light-sensitive photographicmaterial through each of said superimposedmasks separately in such amanner that a halt tone screen is interposed between said drawing andsaid light-sensitive material when the drawing is photographed throughthe half tone mask negative.

15. In a process of producing a drop-out halt tone and line negativefrom an original drawing tone and line mask negative by opaquing thetransparent line portions or said negative, a half tone mask negative,superimposing said halt tone and line-mask positive on said originaldrawing,

' photographing the same through said superimposed,mask positive on alight-sensitive photo-' graphic material, removing said mask positive,superimposing on said drawing said halt tone mask negative. interposingbetween said superimposed drawing-mask negative assembly and saidlight-sensitive photographic material a halt tone screen, andphotographing said drawing through said mask negative and said hall"tone screen on the light-sensitive material without altering therelative position oi the drawing and the light-sensitive material duringthe successive photographing or said drawing on said lightsensitivematerial through said masks.

17. In a process of producing a drop-out hali tone and line negativefrom an original drawin having highlight, line, and tone sections, the vsteps oi photographicaily making a halt tone and having highlight, line,and tone sections, the steps 1 oi photographically making a halt toneand line line mask negative having substantially transparent portionscorresponding to the tone and line sections and substantially opaqueportions corresponding to the highlight sections or the originaldrawing, making from said halt tone and line mask negative by opaquingthe transparent line portions of said negative a halt tone mask negativehaving substantially transparent portions corresponding to the tonesections and substantially opaque portions corresponding to thehighlight and line sections of the original drawmask negative havingsubstantially transparent portions corresponding to the tone and linesections and substantially opaque portionscorresponding to the highlightsections of the original drawing. making from said half tone and linemask negative byopaquing the transparent line portions of said negativea halt tone mask negative having substantially transparent portionscorresponding to the tone sections and substan- I tially opaque portionscorresponding to the highlight and line sections of the originaldrawing;

making from said hali tone mask negative a halt tone mask positivehaving substantially opaque portions corresponding to the tone sectionsand ing, making from said halt tone mask negative a hall. tone maskpositive having substantially opaque portions corresponding to' the tonesections and substantially transparent portions corresponding to thehighlight sections of the original drawing by preparing a photographicprint of said hali' tone mask negative, superimposing said halt tonemask positive on said orginal drawing, photographing the same throughsaid superimposed mask positive on a light-sensitive photographicmaterial, removing said mask positive, superimposing on said drawingsaid half tone mask negative, interposing between said superimposeddrawing-mask negative assembly and said substantially transparentportions corresponding to the highlight and line sections or theoriginal drawing by preparing a photographic print of said hall tonemask negative, superimposing said halt tone mask negative and said halttone mask positive onto said drawing in either succession, and

photograp g said drawing on alight-sensitive photographic materialthrough .each or said superimposed masks separately in such a mannerthat a halt tone screen is interposed between said drawing and saidlight-sensitive materialvwhen the drawing is photographed through thehalf tone mask negative.

16. In a process of producing a drop-out hall'- light-sensitivephotographic material a halt tone screen, and photographing said drawingthrough said mask negative and said halt tone screen on thelight-sensitive material without altering the I relative position of thedrawing and the light- H sensitive material during the successivephotographing of said drawing on said light-sensitive material throughsaid masks.

18. In a process of producing a drop-out half ton negative from anoriginal drawing having highlight and tone sections, the. steps of makinfrom, said drawing a continuous tone negative on tone and line negativefrom an original drawin 1 having highlight, line, and tone sections.thesteps of photographically making a halt tone and line mask negativehaving substantially transparent portions corresponding to the tone andline sections and substantially opaque portions corresponding to thedrawing, making a halt tone and line mask positive having substantiallyopaque portions cor.- responding to the tone and line sectionsandsubstantially transparent portions. correspon n to highlight sectionsof the original I a photographicmaterial consisting of a lightsensitivelayer on a transparent base, treating said continuous tone negativewhile still wet with a photographicreducer until the tones of the tonesections disappear, fixing, washing, and finally drying the thusproduced half tone mask negative having substantially transparentportions corresponding to the tone sections and sub 'stantially opaqueportions corresponding to the highlight sections of the originaldrawing, makthe highlight sections 0! the original drawingby preparing aphotographic print or said halt tone ing a half tone mask positivehaving substantially opaque portions corresponding to the tone sec-.

tions and substantiallytransparent portions corresponding to thehighlight sections of the original drawing by preparing a photographicprint and line mask negative, making from said halt 7g of said'hali tonemask negative, superimposing said masks one after another onto saidoriginal drawing, and photographing said drawing on a light-sensitivephotographic material through each or said superimposed masks separatelyin such a manner that a half tone screen is interposed between saiddrawing and said light-sensitive material when the drawing isphotographed through the half tone mask negative.

19. In a process of producing a drop-out hall tone and line negativefrom an original drawing having highlight, line, and tone sections, thesteps of making from said drawing a continuous tone negative on aphotographic material consisting of a light-sensitive layer on atransparent base, treating said continuous tone negative while still wetwith a photographic reducer until the tones of the tone sectionsdisappear, fixing, washing, and finally drying the thus produced hali'tone and line mask negative having substantially transparent portionscorresponding to the tone and line sections and substantially opaqueportions corresponding to the highlight sections of the originaldrawing, making a half tone and line mask positive having substantiallyopaque portions corresponding to the tone and line sections andsubstantially transparent portions corresponding to the highlightsections of the original drawing by preparing a print of said half toneand line mask negative, making from said half tone and line masknegative by opaquing the transparent line portions of said negative ahalf tone mask negative, superimposing said ball tone mask negative andsaid half tone and line mask positive onto said original drawing ineither succession, and photographing said drawing on a light-sensitivephotographic material through each of said superimposed masks separatelyin such a manner that a half tone screen is interposed between saiddrawing and said light-sensitive material when the drawing isphotographed through the half tone mask negative.

20. In a process "of producing a drop-out half tone and line negativefrom an original drawing having highlight, line, and tone sections, thesteps of making from said drawing a continuous tone negative on aphotographic material consisting of a light-sensitive layer on atransparent base, treating said continuous tone negative while still wetwith a photographic reducer until the tones of the tone sectionsdisappear, fixing, washing, and finally drying the thus produced halttone and line mask negative having substantially transparent portionscorresponding to the tone and line sections and substantially opaqueportions corresponding to the highlight sections of the originaldrawing, making from said half tone and line mask negative by opaquingthe transparent line portions of said negative a half tone mask negativehaving substantially transparent portions corresponding to the tonesections and substantially opaque portions corresponding to thehighlight and line sections of the original drawing, making from saidhalf tone mask negative a half tone mask positive having substantiallyopaque portions corresponding to the tone sections and substantiallytransparent portions corresponding to the highlight and line sections ofthe original drawing by preparing a photographic print of said half tonemask negative, superimposing said half tone mask negative and said halftone mask positive onto said drawing in either succession, andphotographing said drawing on a light-sensitive photographic materialthrough each of said superimposed masks separately in such a manner thata half tone screen is interposed between said drawing and saidlightsensitive material when the drawing is photographed through thehall tone mask negative.-

21. In a process of producing a drop-out half tone and line negativefrom an original drawing having highlight, line, and tone sections, thesteps of making from said drawing a continuous tone negative on aphotographic material consisting of a light-sensitive layer on atransparent base, treating said continuous tone negative while still wetwith a photographic reducer until the tones of the tone sectionsdisappear, fixing, washing, and finally drying the thus produced halftone and line mask negative having substantially transparent portionscorresponding to the tone and line sections and substantially opaque portions corresponding to the highlight sections of the original drawing,making a half tone and line mask positive having substantially opaqueportions corresponding to the tone and line sections and substantiallytransparent portions corresponding to the highlight sections of theoriginal drawing by preparing a print of said half tone and line masknegative, making from said half tone and line mask negative by opaquingthe transparent line portions of said negative a hali tone masknegative, superimposing said hali tone and line mask positive on saidoriginal drawing, photographing the same through said superimposed maskpositive on a light-sensitive photo graphic material, removing said maskpositive, superimposing on said drawing said half tone mask negative,interposing between said superimposed drawing-mask negative assembly andsaid light-sensitive photographic material a half tone screen andphotographing said drawing through said mask negative and said half tonescreen on the light-senstive material without altering the relativeposition of the drawing and the light-sensitive material during thesuccessive photographing of said drawing on said lightsensitive materialthrough said masks.

22. In a process of producing a drop-out half tone and line negativefrom an original drawing having highlight, line, and tone sections, thesteps of making from said drawing a continuous tone negative on aphotographic material con sisting of a light-sensitive layer on atransparent base, treating said continuous tone negative while still wetwith a photographic reducer until the tone of the tone sectionsdisappear, fixing, washing, and finally drying the thus produced halftone and line mask negative having substantially transparent portionscorresponding to the tone and line sections and substantially opaqueportions corresponding to the highlight sections of the originaldrawing, making from said halt tone and line mask negative by opaquingthe transparent line portions of said negative a half tone mask negativehaving substantially transparent portions corresponding to the tonesections and substantially opaque portions corresponding to thehighlight and line sections oi the original drawing, making from saidhalf tone mask negative a halt tone mask positive having substantiallyopaque portions corresponding to the tone sections and substan tiallytransparent portions corresponding to the highlight and line sections ofthe original drawing by preparing a photographic print of said half tonemask negative, superimposing said halt tone mask positive on saidoriginal drawing, photographing the same through said superimposed maskpositive on a light-sensitive photographic material, removing said maskpositive,

superimposing on said drawing said hall tone mask negative interposingbetween said superimposed drawing-mask negative assembly and saidiight-sensitive photographic material a half tone screen andphotographing said drawing through said mask negative and said halt tonescreen on the light-sensitive material without altering the relativeposition of the drawing and the light-sensitive material during thesuccessive photographing of said drawing on said light-sensitivematerial through said masks.

23. In a process of producing a drop-out half [one negative from anoriginal drawing having highlight and tone sections, the steps of makinga half tone mask'negative having substantially transparent portionscorresponding to the tone sections and substantially opaque portionscorresponding to the highlight sections of the original drawing, makinga half tone mask positive having substantially opaque portionscorresponding to the tone sections and substantially transparentportions corresponding to the highlight sections oi the originaldrawing. photographing the original drawing on a light-sensitivephotographic material first through said halt tone mask positive,photographing said original drawing again on the same light-sensitivematerial through said halt tone mask negative and a half tone screeninterposed between said mask negative and the light-sensitivephotographic material, and then placing behind said hall tone masknegative a light-reflecting, preferably white, sheet, and photographingsaid white sheet through said hali tone-screen and half tone masknegative.

24. In a process of producing a drop-out half tone and line. negativefrom an original drawmg, having highlight, line and tone sections, thesteps of making a half tone mask negative having substantiallytransparent portions corresponding to the tone sections andsubstantially opaque portions corresponding to the highlight and linesections oi the original drawing, mak ing a half tone mask positivehaving substantially opaque portions corresponding to the tone sectionsand substantially transparent portions corresponding to the highlightand line sections of the original drawing, photographing thereafter theoriginal drawing on a light-sensitive photographic material firstthrough said half tone mask positive, photographing said originaldrawing again on the same light-sensitive material through said halttone mask negative and a halt tone screen interposed between said masknegative and the light-sensitive photographic material, and then placingbehind said half tone negative at light-reflecting. Preferably white,sheet, and photographing said white sheet through said half tone screenand half tone mask negative.

LASZLO ZUKMANN.

